A particle moves from a point (- 2 hati + 5 hatj)to (4 hatj + 3hatk) when a force of (4 hati + 3hatj) N is applied. How much work has been done by the force?

A particle moves from a point (- 2 hati + 5 hatj)to (4 hatj + 3hatk) w

1.	A particle moves from a point (- 2 hati + 5 hatj)to (4 hatj + 3hatk) when a force of (4 hati + 3hatj) N is applied. How much work has been done by the force?
Answer» 8J 11 J 5 J 2 J Solution :Here, `vec(r_1) = (-2hati +5hatj) m, vec(r_2) = (4 hatj + 3 HATK)m` `VECF = (4 hati + 3 hatj) N, W = ?` Work done by force F in moving from `vec(r_1) ` to `vec(r_2)` `W = vecF . (vec(r_2) - vec(r_1)) = (4hati + 3hatj) . (4 hatj + 3hatk + 2 hati - 5 hatj)` `= (4 hati + 3 hatj) . (2 hati - hatj + 3 hatk) = 8 + (-3) = 5 J`.